Dylan Curran, a technical consultant and web developer, shared some alarming findings about just how much information Facebook and Google store "without you even realising it."

His tweet, which will likely make you delve straight into your Google and Facebook settings, has been retweeted more than 200K times, and gained a shout-out from Edward Snowden.

According to Curran, Google keeps a record of your location every time you turn on your phone, and it keeps a timeline of everywhere you've been since you started using it.

Thought that clearing your browsing history was enough? Think again. Curran says that Google stores "search history across all your devices on a separate database." "So even if you delete your search history and phone history, Google STILL stores everything until you go in and delete everything and you have to do this on all devices."

Curran says that Google also makes an advertisement profile based on your info, which can even include your "possible weight."

It also stores "information on every app and extension you use, how often you use them, where you use them, and who you use them to interact with," including who you talk to on Facebook.